Fix compile warning

Change-Id: I7d88292cbb07b9894ec4c7d60e71f547d93b3c89
diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 780d772..d2786b9 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -1460,7 +1460,7 @@
 
     const uid_t callingUid = IPCThreadState::self()->getCallingUid();
     if (!isTrustedCallingUid(callingUid)) {
-        ALOGW_IF(clientUid != callingUid,
+        ALOGW_IF((uid_t)clientUid != callingUid,
                 "%s uid %d tried to pass itself off as %d", __FUNCTION__, callingUid, clientUid);
         clientUid = callingUid;
     }